Gear shifting mechanism



March 24, 1936. A. o. MCC'OLLUM 2,035,328

GEAR SHIFTING MECHANISM x Filed Jan. 5o, 1955 4'sneetS-sheet 1 INVENTOR.

/l/VDREW 0. 77cCoL./ UM

ATTORNEY.

Marvch 24, 1.936. A.l o. MCcoLLuM 2,035,328 GEARgH-IFMNG MECHANISM Filed Jan; 30, 195s 4 sheets-sheet 2 Il l.

INVENTQR.

ATTORNEY.

24,f19.36.- I' I' A.'o.Mco1.|.x.1My Y 2,035,328

GEAR: SHIFT-:NG MEcHANgsM v Y Filed Jan. 30,1935" 4 sheets-'sheet 's BME! ` INVENTOR.

ATTORNEY.

Patented Mar. 24,1936.-

GEAR SHITING MECHANISM Andrew O. McCollum, Detroit, Mich., assigner to Hydraulic Brake Company, Detroit, Mich., a' corporation of California Application `January 30, 1933, SerialNo. 654,344

7 claims. (ci. fio-545) This invention relates to gear shifting mechanisms and more particularly to hydraulic mechanisms for shifting gears. v I

The invention comprehends means for shifting the gears of a motor vehicle transmission including a remote control means. A preferred embodiment of the invention includes hydraulically actuated pistons arranged in parallelism with the shifting rods of a motor vehicle transmission and l0 so connected or coupled tothe rods that upon movement of the pistons the rods are moved correspondingly. The pistons are :actuated through a remote control including fluid pressure producing means comprising a plurality of cylinders, pistons in the cylinders, and means for selectively actuating the pistons to displace fluid and thereby impose pressure in the cylinders coupled to" the shifting rods.

. The invention aims to provide a hydraulic gear shifting mechanism in .which movement of the gears is accomplished, and so timed that clashingv of the gears is rendered impossible. The fluid pressure producing mechanism or the actuating mechanism and the fluid pressure actuated mechanism are so constructed, arranged and connected that excessive pressures will not develop in either of these mechanisms or i the pipe lines connecting 'the mechanisms.

. An object of the invention is to provide a gear shifting mechanism including a remote control comprising a fluid pressure producing mechamsm. 1

Another object of the invention is to provide a fluid pressure producing mechanism and a fluid pressure actuated mechanism and to so arrange and connect the mechanisms to effectively shift the gears of a motorvehicle transmission.

A further object of the invention is to provide a 4 fluid pressure producing mechanism and a fluid gears of a motor vehicle transmission and to so construct, arrange and connect these instrumentalities that excessive pressure will not develop 4 during operation thereof.

pressure actuated mechanism for shifting the Other objects and structural details of the' Figure-3 is a vertical sectional view of the fluid pressure producing mechanism substantially on line 3 3, Figure 5. v

.Figure-l is a Vertical sectional view substantially on line 4 4, Figure 3. 5

Figure 5is a-sectional View of the fluid pressure actuating'mechanism substantially on line 5 5, Figure 3. Y

' Figure 6 is a sectional view substantially on line 6 6, Figure 3. 10

Figure '7 is a cross-sectional view ofthe fluid pressure actuated mechanism substantially onv line'l 'l, Figure 2. K f

^ Figure 8 is a sectional view of the fluid pressure actuated mechanism substantially on line 8 8, 15 Figure 7, and

Figure 9 is a vertical sectional viewof'the fluid pressure actuated mechanism substantially on line 9 9, Figure 7.

Referring to the drawings for more speciiicde- 20 tails of the invention, I0 represents the floor boards of a motor vehicle body and I2 an instrument board arranged within the body. A fluid pressure ,producingv mechanism indicated generally at I4 is suitably secured to the instrumentz board and connected as by pipe lines to a fluid pressure actuated mechanism indicated generally at I6 bolted or otherwise secured tothe top of a transmission housing I8.

The transmission housing has journaled there- 30 in a driving shaft,y 20, a driven shaft 22 and a counter or jack shaft 24. The driving shaft has secured thereto a driving gear 25 in constant mesh with a gear 26 secured to the jack' shaft.` Rotatably supported on the driven shaft is a gear 35 28 in `constant mesh with a geark 30 keyed tothe counter shaft. The counter shaft also has secured thereon a gear 32 and a gear 34, the latter being in mesh with an idle or reverse gear 3,6.

Thedriven shaft has splined thereon a clutch 38 and a gear 40. The gear 48may be shifted rearwardly to mesh with the idle or reverse gear 36 for the reverse speed position, or the gear. may beA shifted forward to engage the gear 32 for the first forward speed position, and the clutch 38 may be shifted rearwardly to engage the gear f 28 to lock this gear to the driven shaft to drive the transmission through the gear 30, which is the second forward speed position, or, the clutch 38 may be shifted forward to engage the gear 25 50 for the third forward or high speed position. This mechanism is the conventional motor vehicle transmission and forms no part of the present invention.

The transmission housing I8 has bolted or 65 otherwise secured thereto a, fluid pressure actuated mechanism including a cover plate 42 comprising a casting in which are slidably mounted parallel shifting rods 44 and 46, The rod 44 has secured thereto a member 48 engaging the clutch 38, and the rod 46 has secured thereto a member 50 engaging the gear 40, so that, upon shifting, th'e rod 44 or 46, the clutch 38 or the gear 40 is shifted correspondingly. As shown, the shifting rods 44 and 46 have 4cut-away portions 52 and 54 arranged in oppositely disposed relation substantially centrally of the rods, the object of which will hereinafter appear.

The cover plate 42 has a chamber 56 provided with a web 58 and an opening closed as by a cover plate 60, and formed as a part of the cover plate 42 are two sets of opposed cylinders 62, 64, 66, and 68 in parallelism with the shifting rods 44 and 46. The respective cylinders have threaded therein heads 10, 12, 14 and 16 supporting respectively pins 18, 80, 82 and 84, the object of which will hereinafter appear. As shown, the cylinders are connected in pairs by chambers 86 and 88 having openings closed as by cover plates 90 and 92, and the chambers 86 and 88 are arranged in alignment with the chamber 56.

Pistons 94 and 96 are positioned for reciprocation in the cylinders. Each of the pistons includes a cylindrical body portion having a longitudinal bore 98 and a slot or notch |02 arranged equidistant between the respective ends of the body portion. Each of the bores 98 has an increased diameter at the respective ends of the body portion of the piston for the reception of spring-pressed valves |06, |08, and piston heads ||4 and ||6. As shown, the heads have passages communicating with the bore 98 controlled by the respective valves |06 and |08, and suitably secured to the heads are leak-proof cups.

'Ihe chamber 56 and the web 58 therein and the chambers 86 and 88 and the cover plates 90 and 92 for the chambers 86 and 88 are transversely bored to support shafts |22 and |24. The shaft |22 has secured thereto an arm |26 extending into the slot in the shifting rod 44 and an arm |28 extending into the slot in the piston 94. The shaft |24 has similar arms engaging the shifting rod 46 and the piston 96. Because of this structure, upon movement of the piston 94 or 96 corresponding movement of the shifting rod 44 or 46 is accomplished.

The fluid pressure producing means or the actuating mechanism comprises a casting including two pairs of opposed cylinders |34, |36, |38 and |40 arranged in spaced parallel relation, a superimposed reservoir |42 connecting the cylinders, and a dependent chamber |44 communieating with the reservoir. The cylinders are provided with removable heads |46, |48, |50 and |52. The reservoir has an open top, closed as by a cover plate |54, having a filling opening closed by a plug |56. The dependent chamber has an open end to which is fitted a cap |58 provided with ducts |60, |62, |64 and |66.

The duct |66 communicates with a passage |68 leading to a port |10 in the cylinder |36 adjacent to the head thereof; the duct |62 communicates with a passage |12 leading to a port |14 in the cylinder |34 adjacent to the head thereof; the duct |64 communicates with a passage |16 leading to a port |18 in the cylinder |40 adjacent to the head thereof and duct |60 communicates with a passage |80 leading to a port |82 in the cylinder |38 adjacent to the head thereof.

Pistons |84 and |86 are positioned for reciprocation in the respective pairs of opposed cylinders. Ihese pistons have secured to their respective ends leak-proof cups |08, |90, |92 and |94. The pistons are respectively notched as indicated at |96 and |98 for the reception of a slidable pin 200 for retaining the pistons in shifted position, and notches 202 and 204, the purpose of which will hereinafter appear.

Positioned transversely of the reservoir |42 is a rotatable and axially movable shaft 206 movable through an operating lever 208. As shown, the shaft 206 has a iiat portion to which is clamped or otherwise secured an arm 2|0 supporting a pin 2| 2 adapted to engage the notch 202 in the piston |84 or the notch 204 in the piston |86. The free end of the arm 2|0 has thereon a cam 2|4 provided with a plurality of notches 2|6, 2|8 and 220 for retaining the cam and consequently the operating lever in shifted position. This cam cooperates with the stem of a spring-pressed valve 222 controlling the ducts |60, |62, |64 and |66 in the head or cap |58 on the chamber |44, and the valve stem is fitted in the chamber with sufficient clearance to maintain a constant communication between the chamber and the reservoir.

The passage |12 leading to the port |14 in the cylinder |34 is connected-by a pipe line 224 to a port in the cylinder 68 of the actuated mechanism; the passage |68 leading to a port |10 in cylinder |36 is connected by a pipe line 228 to a port in cylinder 66 of the actuated mechanism; the passage |80 leading to a port |82 in cylinder |38 is connected by a pipe line 228 to a port in cylinder 64 of the actuating mechanism; and the passage |16 leading to a port |18 in cylinder 40 is connected by a pipe line 230 to cylinder 62.

Assuming that the system is filled with a suitable hydraulic fluid and that it ls desired to shift the transmission to the reverse position, the operating lever 208 is manipulated to engage the pin 2|2 with the slot 202 in the piston |84 and is then moved in the direction indicated by the arrow designated R to reciprocate the piston |84 and thereby displace the iiuid in cylinder |36.

The fluid is displaced from the cylinder |36 through the pipe line 226 into cylinder 66 causing pressure on the head 8 of the piston 96, thereby moving the piston 96, and this movement is transmitted through interconnecting means to the shifting rod 46. During this movement of the piston 96, the fluid in cylinder 68 is displaced through the pipe line 224 into the cylinder |34, and at tlie end of the stroke of the piston 96 the valve in the head |20 is opened to relieve any excess of pressure on the pipe line 226.

During movement of the operating lever to the position indicated R, the valve 222 is moved to close the ducts |60, |62, |64 and |66 leading from the reservoir to the passages |68, |12, |16 and |80. The valve is opened at the end of the stroke to relieve any pressure in the pipe lines due to expansion of the uid or to supply any decrease in the i'luid due to contraction caused by lower temperature, and upon return of the operating lever to normal position the valve 222 is again opened to relieve any pressure in the pipe lines and to return excess uid due to expansion to the supply reservoir.

When it is desired to shift the transmission gears to the first forward speed position, the operating lever 208 is moved inward to engage the pin 2|2 in the notch 202 in the piston |84 and then in the direction of the arrow indicated F to move the piston |84 and thereby displace the fluid in the cylinder |34vthroughwthe'pipeline 224-1nto the cylinder 84.4 This movement of the piston' |84 causes movement ofthe piston 96 and thismovement of the' piston;,96 is `transmitted through suitable connections to the rod,46 ,to shift lthe* transmission gears tothe first, speed position. I During this movement of the piston 06, the 4fiuid'in the cylinder 66is displaced through the pipe line 226 into the cylinder |36, and at the end` of the `stroke of @piston 96 the valve in the headl |8 of the piston is opened to relieve any excess pressure in the pipe line 224. Upon this movement of the piston 96 the valve 222 is moved to close the ducts connecting the reservoir |42 to the passageways |68, |12, |16 and |80, and is again moved to open the ducts at the end of the stroke of the piston to relieve pressure. When the operating lever is returned to normal position, the valve` is opened to relieve any pressureon the pipe lines.

Now, when it is desired'to shift the transmission gears to the second forward speed position,

the operating lever 208 ismanipulated to move the pin 202 into engagementwith notch 204 in the piston |86 and then in the direction indicated by the arrow designated S to move the piston |86 to displace thefiuid in cylinder |40 through pipe line 230 into cylinder 62, thereby causing piston 94 to move in cylinder 64 and through suitable connections to move rod`44 to shift the gears to the second speed position.

During this movement`"the fluid in cylinder 64 is displaced through pipe line 228 into cylinder |36. At the end of the stroke of piston 04 in cylinder 64, the valve in head ||6 of the piston is opened to relieve any excess fluid in pipe line 230. During movement of. the operating lever to effect this position of the transmission gears, the valve 222 is closed, and is open at the end of the stroke of the piston, and upon return of the operating lever to normal position this valve 222 is opened to relieve any excess pressure in the pipe lines and to `return excess fluid to the reservoir.

When it is desired to shift the gears to the third or high speed position, the operating lever 208 is manipulated to shift the pin 2 I2 to engage the notch 204 in the piston |86 and then in the direction indicated by the arrow designated H. This movement of the operating lever reciprocates the piston |86 to displace fluid in the cylinder |38 through the pipe line 228 into the cylinder 64, causing pressure on the head of piston 94 to move this piston andto move through suitable connections the rod 44 to shift the transmission gears to the high speed position. In this movement the fluid in cylinder 62 is displaced through the pipe line 230 to the cylinder |40, and at the end of the stroke of piston 94 the valve in the head ||4 of the piston 84 is opened to relieve any excess iiuid inthe pipe line 228. During this movement closes the ducts connecting the passages tothe reservoir and at the end of the stroke the valve is opened. Upon shifting the operating lever to the normal position, the valve is again openedA to relieve any pressure on the pipe lines and to return any excess fluid to the reservoir.

While a preferred embodiment of the invention hasbeen described, it is to be understood that this is given merely as an example of the underlying principles of the invention, and since these principles may be incorporated in other specific mechanical structures I do not intendy to v be limitedto the structure shown the valve 222 except where imposed byv the lap-y ysuch limitations are clearly pended claims. f `Having` thus described the various' features of the invention, what I claim as new and desire to secure by'Letters Patent isz- 1. A gear shifting mechanism comprising acov Ier plate, a shifting element supported by'th plate,v a. cylinder arrangedainparallel relation to theshifting element, a piston-movable inthe cylinder, said piston having a longitudinal passage providing a communication between the respective ends of the cylinder, a head on each end of the piston having an orifice registering with the passage, valves in the piston controlling the orifices in the heads, a shaft arranged transversely of the shifting element and the piston, and

arms on the shaft engaging the shifting element and piston respectively.

2. A gear shifting mechanism comprising a cover plate, shifting rods supported thereby, cylinders on the cover plate arranged in parallel relation to one another and to the shifting rods, heads on the respective ends of the cylinders, pistons movable in the cylinders having longi- Y tudinal passages providing'communicationsV between the respective ends of the respective cylinders, heads on the respective ends of the pistons having openings registering with the passages in the pistons, valves in the respective ends of said pistons controlling the openings in the heads of the pistons, means carried by the cylinder heads for tripping the respective valves at the end of the stroke of the respective pistons, shafts arranged transversely to the shifting rods and the pistons, and arms keyed to the shafts engaging the pistons and shifting rods.

3. A gear shifting mechanism comprising fluid pressure means including a reservoir, parallel cylinders supported thereby, pistons movable in `the cylinders, passages connecting the reservoir to the cylinders, a valve controlling the passages, and manually operated means including means in the reservoirfor selectively actuating the pistons and concomitantly closing the valve.

4. A gear shifting mechanism comprising fluid pressure means including a reservoir, parallel cylinders formed integral therewith, Vpassages y connecting the reservoir to the cylinders, pistons movable in the cylinders, heads on the respective ends of the pistons, means for locking either of the pistons against movement during movement of the other, hand operated means for selectively actuating the pistons including meansl for closing the passages connecting the reservoir to the rcylinders during movement of keither of the pistons.

5. A gear shifting mechanism comprising fluid pressure means including a reservoir, cylinders formed integral therewith, passages connecting the cylinders to the reservoir, a valve controlling the passages, pistons movable in the cylinders,

heads on the respective ends of the pistons, leakproof cups on the heads, a slidable rockable shaft `arranged transversely to the pistons, means on thecylinders, a valve ln the chamber for control of the passages, pistons movable in thecyllnders, and means in the reservoir for selectively actuating thepistons and concomitantly closing the valve. Y v

7. A gear shifting mechanism comprising fluid actuated members, means connecting the members to the shifting elements of the mechanism, a fluid pressure device including a reservoir, parallel cylinders Vsupported in the bottom thereof, a uid pressure delivery means connecting the respective ends of the cylinders to the fluid actuated members, a chamber communicating with the reservoir and depending from the bottom thereof between the cylinders, passages providing communication between the chamber and the cylinders, a valve controlling the passages, double end pistons movable in the cylinders, and means in the reservoir for selectively actuating the pistons including means for actuating the valve.

ANDREW O. MCCOLLUM. 

